In what a federal judge described as a shocking case of misconduct, a Baltimore man who was a key witness in a 1991 police brutality case was himself unconstitutionally harassed by a city officer in retaliation for his testimony.

U.S. District Judge Marvin J. Garbis, in a strongly worded written order, said Officer Richard Iglehart acted improperly when he stopped Matthias S. Carter without cause when Mr. Carter was driving in Southeast Baltimore two years ago.

Officer Iglehart's action was "planned for months and was intended as a 'payback' for Carter's testimony" in the 1991 brutality case, said Judge Garbis, who heard Mr. Carter's civil suit without a jury.

"There was, without question, an evil motive for the unconstitutional stop -- the motive of harassing Carter and demonstrating to Carter [and others who would hear about it] that those who have the temerity to testify against Southeastern District police officers are going to regret having done so," Judge Garbis said.

Judge Garbis in May upheld Mr. Carter's claim that his rights were violated and awarded him damages.

Last week, the city's Board of Estimates approved payment of a $28,097 judgment to Mr. Carter -- $15,500 in damages, plus $12,597 in legal fees.

Judge Garbis said that the officer's action "strikes at the heart of that part of our legal system designed to protect civil rights and "at the effective functioning of the courts."

"There cannot be any toleration of harassment of witnesses testifying in our courts by any person. Even more so, there will be no toleration of police harassment of witnesses," the judge said.

Mr. Carter, 53, a former police equipment salesman, spent the night in jail after the stop on charges -- later dismissed -- of illegal possession of handguns and deadly weapons. He said this week that he isn't satisfied with the amount of the award -- or the fact that the officer who violated his constitutional rights is still on the streets.

"Fifteen thousand dollars? It should have been a whole lot more," he said.

As for Officer Iglehart, then assigned to the Southeastern District and now a patrolman in the Eastern District, Mr. Carter said: "He should have lost his job or been severely punished."

Since Judge Garbis issued his order against Officer Iglehart, the Baltimore Police Department has begun its own investigation.

"The facts and circumstances are being reviewed to determine whether departmental disciplinary action is appropriate," said Officer Robert W. Weinhold Jr., a police spokesman.

Efforts to reach Officer Iglehart, 34, were unsuccessful. His attorney, Robert C. Verderaime, said he believes his client acted properly but there were no grounds for an appeal.

"The court drew inferences from the testimony and resolved them in favor of Mr. Carter," he said. "While we disagree with the findings, that's what litigation is all about."

Two other officers who were also sued by Mr. Carter for participating in the arrest were found not liable.

Matthias Carter's case is rooted in a Nov. 4, 1989, incident. At the time, he was working for Valley Police Supply in Parkville, a job for which he had a permit to carry a gun. He was moonlighting as a cashier at a 7-Eleven store in the 6600 block of Holabird Ave. in Southeast Baltimore.

Shortly after midnight, on the street outside the store, Mark Hafner fired a blast from a shotgun in the air and several through his windshield, according to court records.

Confronted by officers minutes later, Mr. Hafner dropped his gun and was arrested.

Mr. Carter, who went to see what was happening, said he saw Mr. Hafner handcuffed face down on the ground, with "one officer lying across his feet, and another kicking the hell out of him."

Mr. Hafner was found not criminally responsible for his behavior and spent two years in state mental hospitals, according to his attorney, Allan Heneson, who also came to represent Mr. Carter in his suit against the police.

Mr. Hafner filed suit against the officers who arrested him, charging that they used excessive force. Mr. Carter was a key witness in the trial.

In September of 1991, Mr. Hafner won a $50,000 judgment against the arresting officers -- who did not include Officer Iglehart.

Even before the case was decided, Mr. Carter, who had been friendly with several police officers in the Southeastern District, said he noticed a change in the relationships. "Any time I saw any of the officers, they avoided me or gave me dirty looks," he said.

Not long after the decision in the Hafner case, Mr. Carter quit his job at the 7-Eleven. He also left Valley Police Supply and went to work selling police equipment for the Maryland Troopers Association Store in Pikesville. Because his new job did not require him to sell guns, his gun permit was not renewed.

Late on the evening of April 29, 1992, he said, he was returning from a trip to the Eastern Shore making sales calls to police agencies and going target shooting with a friend. When he reached Baltimore, he stopped for coffee at the 7-Eleven where he used to work.

While he was in the store, he was spotted by a Southeastern District officer, who radioed Officer Iglehart, according to court records. Officer Iglehart, who had found out months before that Mr. Carter's gun permit had expired, drove to the 7-Eleven and decided to stop Mr. Carter after he left the store, records show.

Almost as soon as Mr. Carter drove onto Holabird Avenue, he was pulled over by Officer Iglehart.

"Carter's driving was not such as to provide reasonable cause for a stop for any traffic purposes," Judge Garbis wrote. "Iglehart stopped Carter because, and solely because, he wished to harass him."

Mr. Carter had a loaded .22 Derringer and an unloaded .357 Magnum in his car, records show. He also had a trunk full of police equipment, including a blackjack. He was charged with various handgun and deadly weapons violations.

Officer Iglehart's statement of charges against Mr. Carter included the "false statement" that the officer had seen Mr. Carter drunk on several occasions, apparently to "provide a fabricated justification for the stop of Carter," Judge Garbis noted.

The charges against Mr. Carter were dismissed in October 1992, when a Baltimore District judge threw out the evidence, ruling that it had been improperly obtained.

Mr. Carter, who left his job at the Maryland Troopers Association Store shortly after his arrest and is currently unemployed, said his experience has changed his attitude toward police.

"I don't trust a cop anymore," he said. "I used to consider myself a good friend of a lot of cops. Now I feel a cop's only friend is another cop."